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by Catherine Perham
Maine is host to many "bad", that is to say invasive, plants. These plants displace native flora, thus eliminating the natural food and cover for our wildlife and ultimately threatening rare species of both animals and plants.
The State of Maine has an excellent program to deal with aquatic invasives, and has successfully removed several bodies of water from its list of those contaminated with invasive plants. We are a little behind in recognizing, removing, and preventing the spread and introduction of terrestrial invasive plants, but that is being remedied by folks like Nancy Olmstead, Invasive Plant Biologist with the Maine Natural Areas Program of the Maine Department of Agriculture, Conservation and Forestry. We can all help Nancy and eradicate bad plants, especially on our own property.
There are several steps to this plan, the first of which is to identify the plants that you have. Many are easy to spot once your eye has learned the characteristics of the plants. Nancy has identified thirteen plants that are especially problematic in Maine; these include Norway maple, yellow iris, shrubby honeysuckle, burning bush, purple loosestrife, and ornamental jewelweed. Common reed, or Phragmites australis, is becoming a problem in wetland areas. Unlike the native Phragmites americanus, this reed forms dense stands that do not allow nesting. Become familiar with some of these plants, and walk your property with an eye towards identifying unwanted invaders.
Many "bad plants," such as garlic mustard and Japanese honeysuckle, were deliberately introduced to our state when they were planted in gardens or used for landscaping. Unfortunately, some of the traits that made these plants popular, such as ease of propagation or attraction to birds, also allows them to naturalize easily and invade our unwary soil.
There is work afoot (thanks to Nancy and others) to establish a "Do Not Sell" list for Maine nurseries, in order to halt the introduction of noxious species by unwary consumers. Most of us just assume that exotic invasives are not for sale in the local garden center, but to date this is not true. Ask for native species when you buy.
You don't have to eradicate your invasive plants alone! Both the NRCS & Kennebec SWCD are concerned about invasive plants and animals that are threatening to overrun our state's natural ecosystems and they can help you. The NRCS just sponsored an Invasive Terrestrial Plants seminar with Nancy Olmstead. Check the NRCS website to learn more. The NRCS has helped treat 20 million acres since 2008. If you have questions, contact the Augusta Service Center and we may be able to provide assistance.
How can you get rid of an invasive plant infestation? There are a lot of answers to this, depending on what you find. Now is a good time to walk your property, preferably with a plant expert, as plants are in full growth and perhaps even in flower or fruit, both of which make the plant easier to identify for the amateur. Wear gloves if you want to pull the plants as you find them. Some of them, like Rosa multiflora, are armed!
If you throw the plants into a black plastic garbage bag, you can place the whole mess in the sun and the heat or solarization will cook the plants and their seeds until they are no longer viable. The more woody the plants, the longer this process takes. The resulting gunk can theoretically be used as compost but you may be happier disposing of it.
For most invasive plants, burning is also an acceptable non-chemical method of destruction. If you do this make sure to get a burn permit. No marshmallows if you are burning a toxic plant such as woody nightshade!
You can find rental goats who willingly eat many invasives, including Japanese knotweed. If you decide to use chemicals, please consult an expert and mind that nothing runs or drifts into our lakes and streams!
Remember, there is a lot to do in order to protect water quality. Managing invasive plants is part of that effort.
Guest columnist Catherine Perham works for the Natural Resources Conservation Service of the U.S. Department of Agriculture.